. Ed Pegg Jr.'s site has pages on tiling, packing, and related problems involving polyominos, polyiamonds, polyspheres, and related shapes.

Jorge Luis Mireles explains finite and infinite spirals made up of polyforms.

Colonel Sicherman asks what fraction of the triangles need to be removed from a regular triangular tiling of the plane, in order to make sure that the remaining triangles contain no copy of a given polyiamond.

Mathforum. This Geometry problem of the week asks whether a six-point star can be dissected to form eight distinct hexiamonds.

Peter Turney lists the 261 polycubes that can be folded in four dimensions to form the surface of a hypercube, and provides animations of the unfolding process.

Java applet demonstres that this tetromino-packing game is a forced win for the side dealing the tetrominoes. Complete with mathematical proof. [Java]

Joseph Myers and John Berglund found a polyhex that must be placed in two different ways in a tiling of a plane, such that one placement occurs twice as often as the other.

Anna Gardberg makes pentominoes out of sculpey and agate.

George Huttlin explains and illustrates these shapes composed of 6 equilateral triangles, which in turn tiles different forms.

George Huttlin shares some ramblings in the world of polyominoes.